Surrounding rock movement mechanism and cable reinforcement support technology for gob-side entry retaining in the dynamic pressure area of deep fully-mechanized mining face
The surrounding rock for gob-side entry retaining in a deep fully mechanized mining face is subjected to multiple coupled stress effects,and problems such as roof caving and bulging urgently need to be solved.In this study,by taking the 2611 working face of Juji Coal Mine as the engineering back-ground,the deformation characteristics of surrounding rock for gob-side entry retaining in the dynamic pressure area with different support patterns including anchor rod,anchor rod-anchor cable,and anchor rod-anchor cable-reinforcement anchor cable were explored by means of theoretical analysis,simulation analysis,and on-site testing and monitoring.Based on the theory of bending moment superposition during rotary subsidence of roof,a structural mechanical model of surrounding rock for gob-side entry retaining in the dynamic pressure area was constructed,and the calculation formula of roof bending subsidence was in-novatively deduced.With the aid of the above model and formular,the subsidence amounts of roadway roof under different support schemes were calculated.Furthermore,with full consideration of the characte-ristics of FLAC3D and UDEC software,the stress and deformation characteristics of surrounding rock for gob-side entry retaining under roof cutting and non-roof cutting conditions were comparatively simulated.By doing so,the interactions between the surrounding rock and anchor rods,anchor cables,and reinforce-ment anchor cables were elucidated.Among them,reinforcement anchor cables,by virtue of their strong preload,long action distance,and stress transfer function,are capable of effectively suppressing roof de-lamination and inducing the transfer of the peak stress of the surrounding rock to the deep.The on-site mo-nitoring results indicate that after the application of reinforcement anchor cables,the roadway roof for gob-side entry retaining merely subsides by 90 mm,suggesting that reinforcement anchor cables contribute to ensuring safe and efficient recovery of deep fully mechanized mining face.
万方数据
维普
